This invention relates generally to power steering systems for motor vehicles, and more particularly to a magnetorheological steering damper.
Rotary dampers have been installed in steering assemblies of motor vehicles to dampen the amount of vibration detected by the vehicle operator from such variables as vehicle speed, road bumps, wheel alignment, wheel chatter, and tread wear. Rotary dampers of this type reduce the amount of vibration transferred to the vehicle operator by resisting rotational velocity generated from a pinion associated with the steering assembly. The rotational velocity is resisted by torque generated by the rotary damper, thereby reducing vibration. The torque is derived from a clutch-like resistance generated by a fluid when a rotor disposed within the vibration damper assembly is operatively connected to the pinion and receives rotational velocity from the pinion.
The present invention is a damper for dampening vibrations of a rotatable steering shaft of a motor vehicle. The damper comprises a rotor, and means for rotating the rotor at a rate proportional to and greater than rotation of the steering shaft. Magnetorheological fluid is disposed at least partially around the rotor, and has a viscosity variable to vary a load on the rotor.
Accordingly, it is an object of the present invention to provide an improved damper for motor vehicle steering systems.
Another object of the present invention is to provide a damper of the type described above in which the means for rotating the rotor includes gears of different diameters.
Still another object of the present invention is to provide a damper of the type described above in which the means for rotating the rotor includes a planetary drive system.
Still another object of the present invention is to provide a damper of the type described above which minimizes gear lash.
These and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.